# SPDX-License-Identifier: GPL-2.0

  menu "UML-specific options"
  
  config UML
  	bool
  	default y
  	select ARCH_HAS_KCOV

  	select ARCH_NO_PREEMPT

  	select HAVE_ARCH_AUDITSYSCALL
  	select HAVE_ARCH_SECCOMP_FILTER

  	select HAVE_ASM_MODVERSIONS

  	select HAVE_UID16
  	select HAVE_FUTEX_CMPXCHG if FUTEX
  	select HAVE_DEBUG_KMEMLEAK

  	select HAVE_DEBUG_BUGVERBOSE

  	select NO_DMA

  	select GENERIC_IRQ_SHOW
  	select GENERIC_CPU_DEVICES
  	select GENERIC_CLOCKEVENTS
  	select HAVE_GCC_PLUGINS

  	select SET_FS

  	select TTY # Needed for line.c
  
  config MMU
  	bool
  	default y
  
  config NO_IOMEM
  	def_bool y
  
  config ISA
  	bool
  
  config SBUS
  	bool

  config TRACE_IRQFLAGS_SUPPORT
  	bool
  	default y
  
  config LOCKDEP_SUPPORT
  	bool
  	default y
  
  config STACKTRACE_SUPPORT
  	bool
  	default y
  	select STACKTRACE
  
  config GENERIC_CALIBRATE_DELAY
  	bool
  	default y
  
  config HZ
  	int
  	default 100
  
  config NR_CPUS
  	int
  	range 1 1
  	default 1

  source "arch/$(HEADER_ARCH)/um/Kconfig"

  config MAY_HAVE_RUNTIME_DEPS
          bool

  config STATIC_LINK
  	bool "Force a static link"

  	depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || !MAY_HAVE_RUNTIME_DEPS

  	help
  	  This option gives you the ability to force a static link of UML.
  	  Normally, UML is linked as a shared binary.  This is inconvenient for
  	  use in a chroot jail.  So, if you intend to run UML inside a chroot,
  	  you probably want to say Y here.
  	  Additionally, this option enables using higher memory spaces (up to
  	  2.75G) for UML.

  	  NOTE: This option is incompatible with some networking features which
  	  depend on features that require being dynamically loaded (like NSS).

  config LD_SCRIPT_STATIC
  	bool
  	default y
  	depends on STATIC_LINK
  
  config LD_SCRIPT_DYN
  	bool
  	default y
  	depends on !LD_SCRIPT_STATIC

  	select MODULE_REL_CRCS if MODVERSIONS

  config HOSTFS
  	tristate "Host filesystem"
  	help

  	  While the User-Mode Linux port uses its own root file system for
  	  booting and normal file access, this module lets the UML user
  	  access files stored on the host.  It does not require any
  	  network connection between the Host and UML.  An example use of
  	  this might be:

  	  mount none /tmp/fromhost -t hostfs -o /tmp/umlshare

  	  where /tmp/fromhost is an empty directory inside UML and
  	  /tmp/umlshare is a directory on the host with files the UML user
  	  wishes to access.

  	  For more information, see
  	  <http://user-mode-linux.sourceforge.net/hostfs.html>.

  	  If you'd like to be able to work with files stored on the host,
  	  say Y or M here; otherwise say N.

  
  config MCONSOLE
  	bool "Management console"
  	depends on PROC_FS
  	default y
  	help

  	  The user mode linux management console is a low-level interface to
  	  the kernel, somewhat like the i386 SysRq interface.  Since there is
  	  a full-blown operating system running under every user mode linux
  	  instance, there is much greater flexibility possible than with the
  	  SysRq mechanism.
  
  	  If you answer 'Y' to this option, to use this feature, you need the
  	  mconsole client (called uml_mconsole) which is present in CVS in
  	  2.4.5-9um and later (path /tools/mconsole), and is also in the
  	  distribution RPM package in 2.4.6 and later.
  
  	  It is safe to say 'Y' here.

  
  config MAGIC_SYSRQ
  	bool "Magic SysRq key"
  	depends on MCONSOLE
  	help
  	  If you say Y here, you will have some control over the system even
  	  if the system crashes for example during kernel debugging (e.g., you
  	  will be able to flush the buffer cache to disk, reboot the system
  	  immediately or dump some status information). A key for each of the
  	  possible requests is provided.
  
  	  This is the feature normally accomplished by pressing a key
  	  while holding SysRq (Alt+PrintScreen).
  
  	  On UML, this is accomplished by sending a "sysrq" command with
  	  mconsole, followed by the letter for the requested command.
  
  	  The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
  	  unless you really know what this hack does.
  
  config KERNEL_STACK_ORDER
  	int "Kernel stack size order"

  	default 2 if 64BIT
  	range 2 10 if 64BIT
  	default 1 if !64BIT

  	help
  	  This option determines the size of UML kernel stacks.  They will
  	  be 1 << order pages.  The default is OK unless you're running Valgrind
  	  on UML, in which case, set this to 3.

  	  It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
  	  older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
  	  increase in the size of the state which needs to be saved when handling

  	  signals.

  
  config MMAPPER
  	tristate "iomem emulation driver"
  	help
  	  This driver allows a host file to be used as emulated IO memory inside
  	  UML.

  config PGTABLE_LEVELS
  	int
  	default 3 if 3_LEVEL_PGTABLES
  	default 2

  config UML_TIME_TRAVEL_SUPPORT
  	bool
  	prompt "Support time-travel mode (e.g. for test execution)"

  	# inf-cpu mode is incompatible with the benchmarking
  	depends on !RAID6_PQ_BENCHMARK

  	depends on !SMP

  	help
  	  Enable this option to support time travel inside the UML instance.
  
  	  After enabling this option, two modes are accessible at runtime
  	  (selected by the kernel command line), see the kernel's command-
  	  line help for more details.
  
  	  It is safe to say Y, but you probably don't need this.

  endmenu

  source "arch/um/drivers/Kconfig"